1. Field of the Invention
The present invention relates to a data communication apparatus and, more particularly, to a data communication apparatus which relays and sends data sent from a relay request station to prestored multi-address called stations in a multi-address calling mode on the basis of a relay request from the relay request station.
2. Related Background Art
In a conventional data communication apparatus such as a facsimile apparatus, a multi-address calling function for sending the same image data to a plurality of called stations is known. In addition, a relay multi-address calling system as a combination of the multi-address calling function and a relay function is also known. In this system, a relay station which received an instruction from a request station performs multi-address calling to multi-address called stations registered in advance. U.S. Pat. No. 4,785,355 and U.S. Pat. No. 4,974,097 which is a continuation of U.S. patent application Ser. No. 120,104 filed on Nov. 13, 1987, now abandoned, are known as applications associated with relay multi-address calling, and U.S. Pat. Nos. 4,772,955 and 4,845,569, and U.S. patent application Ser. No. 387,981 filed on Aug. 1, 1989, which is allowed, are known as applications associated with multi-address calling.
In the conventional relay multi-address calling system, data is unconditionally sent to all the registered multi-address called stations. For this reason, if a relay request station is registered as a multi-address called station in a relay station, since data is sent to all the registered multi-address called stations, data is unnecessarily sent to a relay request station as a source station.